The Republic of China (referred as ROC Rebels in-game) is a faction that opposes the People's Republic of China in a civil war. They formed out of the ashes of the old nationalist China that ruled the country before the communists took over, and fight to free their country once more.
During the Second World War, The Republic of China was overthrown by Communist forces, who were being supported by Russia. The Communists soon formed into a new governing party: The People's Republic of China. However, many insurgents still loyal to the old, pre-communist Republic of China continue to fight against PRC forces, creating some political instability from within.
During the Third World War, PsiCorps gave the ROC rebels an opportunity to capture a Psychic Beacon and take several PRC divisions under their control, majorly increasing their fighting strength. However, this was all a ruse by Yuri as he simply used the rebels for his own ends.
When the PRC government requested the destruction of the Psychic Beacon controlling their forces, Russia responded by sending Volkov and Chitzkoi (as they cannot be mind controlled due to their cybernetic implants) along with a remote controlled Kirov Airship.
They escorted the Kirov to the target and dropped the airship on top of the Beacon, destroying it. The PRC divisions were soon back under loyalist control and executed many ROC rebels nearby. Several escaped, living to fight another day.
The ROC rebels used stolen Soviet equipment in order to fight their enemies as they did not have the means of making their own vehicles and weapons.